Transcriptome profiling reveals mechanisms for the evolution of insect seasonality
Crista B Wadsworth1, Erik B Dopman1
1Department of Biology, Tufts University, 200 Boston Ave, Suite 4700, Medford, MA 02155, USA crista.wadsworth@tufts.edu erik.dopman@tufts.edu.
The Journal of Experimental Biology
|September 30, 2015
Summary
Evolutionary shifts in insect seasonality, like in the European corn borer moth, are driven by distinct molecular mechanisms. These changes in diapause termination involve unique genetic switches and gene regulatory networks, aiding adaptation.
Area of Science:
- * Evolutionary biology
- * Molecular genetics
- * Climate change adaptation
Background:
- * Rapid evolutionary changes in seasonal timing are crucial for ecological speciation and climate change resilience.
- * Molecular mechanisms underlying shifts in animal seasonality remain largely unknown.
- * The European corn borer moth (Ostrinia nubilalis) exhibits evolved differences in seasonal emergence between E-strain and Z-strain adults, linked to larval diapause termination.
Purpose of the Study:
- * To investigate the molecular mechanisms and genetic basis of divergent seasonality in the European corn borer moth.
- * To identify candidate genes and regulatory pathways involved in the differential timing of diapause termination between E-strain and Z-strain Ostrinia nubilalis.
- * To compare gene expression patterns during diapause termination between the two strains and with other insect species.
Main Methods:
- * Transcriptome sequencing of diapause termination in E-strain and Z-strain Ostrinia nubilalis.
- * Analysis of regulatory and amino acid changes associated with seasonal timing divergence.
- * Identification of candidate genes within a known quantitative trait locus (QTL).
Main Results:
- * 48 candidate genes were nominated, including those in insulin signaling and circadian rhythm pathways.
- * Genome-wide transcriptional activity was low during extended Z-strain diapause termination.
- * E-strain diapause termination showed rapid regulatory changes in cell cycle, hormone production, and stress response genes.
- * Gene expression during diapause termination in Ostrinia shares similarities with flies, but timing-related genes are species-specific.
Conclusions:
- * Divergent seasonality in Ostrinia nubilalis is driven by species-specific genetic switches.
- * These genetic switches restructure conserved gene regulatory networks to direct organisms into distinct diapause phases.
- * Understanding these mechanisms is key to predicting insect adaptation to environmental changes.
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